/*
 * @Author: your name
 * @Date: 2021-10-09 13:50:19
 * @LastEditTime: 2021-10-09 13:54:44
 * @LastEditors: Please set LastEditors
 * @Description: In User Settings Edit
 * @FilePath: \test_algorithm\threadsafe_queue.hpp
 */
#include <queue>
#include <mutex>
#include <condition_variable>
#include <initializer_list>

template<typename T>
class threadsafe_queue{
private:
    // data_queue 访问信号量
    mutable std::mutex mut;
    mutable std::condition_variable data_cond;
    std::queue<T> data_queue;
public:
    using value_type= typename std::queue<T>::value_type;
    using container_type = typename std::queue<T>::container_type;
    threadsafe_queue()=default;
    threadsafe_queue(const threadsafe_queue&)=delete;
    threadsafe_queue& operator=(const threadsafe_queue&)=delete;
    /*
     * 使用迭代器为参数的构造函数,适用所有容器对象
     * */
    template<typename _InputIterator>
    threadsafe_queue(_InputIterator first, _InputIterator last){
        for(auto itor=first;itor!=last;++itor){
            data_queue.push(*itor);
        }
    }
    explicit threadsafe_queue(const container_type &c):data_queue(c){}
    /*
     * 使用初始化列表为参数的构造函数
     * */
    threadsafe_queue(std::initializer_list<value_type> list):threadsafe_queue(list.begin(),list.end()){
    }
    /*
     * 将元素加入队列
     * */
    void push(const value_type &new_value){
        std::lock_guard<std::mutex> lk(mut);
        data_queue.push(std::move(new_value));
        data_cond.notify_one();
    }
    /*
     * 从队列中弹出一个元素,如果队列为空就阻塞
     * */
    value_type wait_and_pop(){
        std::unique_lock<std::mutex> lk(mut);
        data_cond.wait(lk,[this]{return !this->data_queue.empty();});
        auto value = std::move(data_queue.front());
        data_queue.pop();
        return value;
    }
    /*
     * 从队列中弹出一个元素,如果队列为空返回false
     * */
    bool try_pop(value_type& value) {
        std::lock_guard<std::mutex> lk(mut);
        if(data_queue.empty())
            return false;
        value = std::move(data_queue.front());
        data_queue.pop();
        return true;
    }
    /*
     * 返回队列是否为空
     * */
    auto empty() const->decltype(data_queue.empty()) {s
        std::lock_guard<std::mutex> lk(mut);
        return data_queue.empty();
    }
    /*
     * 返回队列中元素数个
     * */
    auto size() const->decltype(data_queue.size()) {
        std::lock_guard<std::mutex> lk(mut);
        return data_queue.size();
    }
}; /* threadsafe_queue */
